Hidalgo H A, Helmke R J, German V F, Mangos J A
Department of Pediatrics, University of Texas Health Science Center, San Antonio 78284-7815.
Infect Immun. 1992 Jan;60(1):1-7. doi: 10.1128/iai.60.1.1-7.1992.
There is evidence that alveolar macrophages (AM) play a role in the clearing of Pneumocystis carinii from the lungs. To investigate the mechanisms involved in this process, we studied in vitro the induction of an oxidative burst by P. carinii in a cell line of macrophages (NR8383) and AM from normal rats. P. carinii was added to macrophage monolayers (10(6) cells), and the H2O2 produced after 4 h of incubation was measured. Both NR8383 macrophages and normal rat AM produced H2O2 in response to P. carinii cysts and trophozoites isolated from dexamethasone-treated rats, although the amount of H2O2 induced in AM from normal rats was larger. NR8383 macrophages bound and phagocytized both P. carinii cysts and trophozoites and produced increasing amounts of H2O2 as a dose-related response to cysts and trophozoites. Opsonization of P. carinii with normal rat serum increased H2O2 production by both types of macrophages; this enhancement was decreased, but not abolished, when the serum was first depleted of complement by heat treatment. These findings demonstrate that NR8383 macrophages and normal rat AM produce an oxidative burst in response to P. carinii and that this response is enhanced by complement.
有证据表明肺泡巨噬细胞（AM）在清除肺部卡氏肺孢子虫方面发挥作用。为了研究这一过程涉及的机制，我们在体外研究了卡氏肺孢子虫对巨噬细胞系（NR8383）和正常大鼠AM中氧化爆发的诱导作用。将卡氏肺孢子虫添加到巨噬细胞单层（10⁶个细胞）中，测量孵育4小时后产生的过氧化氢（H₂O₂）。NR8383巨噬细胞和正常大鼠AM对从地塞米松处理的大鼠中分离出的卡氏肺孢子虫囊肿和滋养体均产生H₂O₂，尽管正常大鼠AM中诱导产生的H₂O₂量更大。NR8383巨噬细胞结合并吞噬卡氏肺孢子虫囊肿和滋养体，并作为对囊肿和滋养体的剂量相关反应产生越来越多的H₂O₂。用正常大鼠血清调理卡氏肺孢子虫可增加两种类型巨噬细胞的H₂O₂产生；当血清首先通过热处理去除补体时，这种增强作用减弱但未消除。这些发现表明，NR8383巨噬细胞和正常大鼠AM对卡氏肺孢子虫产生氧化爆发，并且这种反应通过补体增强。
